Welcome to the slippery slope Carl! (unfortunate first name round these parts, unlucky!

)
Not quite sure what you are after, but I'll throw a load of stuff at you and see if any of it is of interest...
I have only done one pool-based triathlon so I'll use that as my basis and assume yours is similar.
Once your swim is done hop out of the pool, give your coloured swimcap to the attendant (assuming they are using that system) and take your goggles off. You'll jog out of the pool out to the transition where your bike is waiting. (Rehearse the route beforehand and remember where your bike is!)
Depending on what you are wearing, get dressed! No nuduity in transition, so you're going to be cycling in whatever you swam in. If you have tri shorts (quick drying lycra shorts with a small pad in for cycling comfort but not large enough to affect running) then they are the best. However they are not normally cheap so you may just want to pull some cycling or other shorts over your swimming trunks for your first tri to see how you get on? Or go old school and race in your budgie smugglers!
Putting on clothes when wet is a right hassle, so if you need to put on a top you might want to give yourself a quick towel down (I'm assuming you are not trying to save every last second?) before pulling on a top to cycle and run in.
Decide beforehand if you are going to wear socks. For a sprint distance most dont bother but its more comfortable with socks on. Again socks are hard to put on wet feet, so roll them down beforehand with some talc in to make it a little easier. Put on your bike shoes or trainers, put on your helmet and shades (and gloves if you are bothering), grab your bike and jog to the mount line where a marshall will tell you to get on and go catch the person infront!
Someone will probably be along who's done Wilmslow and be able to give you more specific advice.
If you can put some slicks on your MTB then that will save you a lot of time, as will turning off any suspension, which wastes energy on a road.
I'm sure you'll get more advice, but feel free to ask away!